import {
  action,
  observable
} from 'mobx-miniprogram'
export const store = observable({
  numA: 1,
  numB: 2,
  get sum() {
    return this.numA + this.numB
  },
  changnumA1: action(function (step) {
    this.numA += step
  }),
  changnumA2: action(function (step) {
    this.numA -= step
  }),
})